// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <string>

#include "base/memory/linked_ptr.h"
#include "base/strings/stringprintf.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace {

int num = 0;

std::string history;

// Class which tracks allocation/deallocation
struct A {
    A()
        : mynum(num++)
    {
        history += base::StringPrintf("A%d ctor\n", mynum);
    }
    virtual ~A() { history += base::StringPrintf("A%d dtor\n", mynum); }
    virtual void Use() { history += base::StringPrintf("A%d use\n", mynum); }
    int mynum;
};

// Subclass
struct B : public A {
    B() { history += base::StringPrintf("B%d ctor\n", mynum); }
    ~B() override { history += base::StringPrintf("B%d dtor\n", mynum); }
    void Use() override { history += base::StringPrintf("B%d use\n", mynum); }
};

} // namespace

TEST(LinkedPtrTest, Test)
{
    {
        linked_ptr<A> a0, a1, a2;
        a0 = a0;
        a1 = a2;
        ASSERT_EQ(a0.get(), static_cast<A*>(NULL));
        ASSERT_EQ(a1.get(), static_cast<A*>(NULL));
        ASSERT_EQ(a2.get(), static_cast<A*>(NULL));
        ASSERT_TRUE(a0 == NULL);
        ASSERT_TRUE(a1 == NULL);
        ASSERT_TRUE(a2 == NULL);

        {
            linked_ptr<A> a3(new A);
            a0 = a3;
            ASSERT_TRUE(a0 == a3);
            ASSERT_TRUE(a0 != NULL);
            ASSERT_TRUE(a0.get() == a3);
            ASSERT_TRUE(a0 == a3.get());
            linked_ptr<A> a4(a0);
            a1 = a4;
            linked_ptr<A> a5(new A);
            ASSERT_TRUE(a5.get() != a3);
            ASSERT_TRUE(a5 != a3.get());
            a2 = a5;
            linked_ptr<B> b0(new B);
            linked_ptr<A> a6(b0);
            ASSERT_TRUE(b0 == a6);
            ASSERT_TRUE(a6 == b0);
            ASSERT_TRUE(b0 != NULL);
            a5 = b0;
            a5 = b0;
            a3->Use();
            a4->Use();
            a5->Use();
            a6->Use();
            b0->Use();
            (*b0).Use();
            b0.get()->Use();
        }

        a0->Use();
        a1->Use();
        a2->Use();

        a1 = a2;
        a2.reset(new A);
        a0.reset();

        linked_ptr<A> a7;
    }

    ASSERT_EQ(history,
        "A0 ctor\n"
        "A1 ctor\n"
        "A2 ctor\n"
        "B2 ctor\n"
        "A0 use\n"
        "A0 use\n"
        "B2 use\n"
        "B2 use\n"
        "B2 use\n"
        "B2 use\n"
        "B2 use\n"
        "B2 dtor\n"
        "A2 dtor\n"
        "A0 use\n"
        "A0 use\n"
        "A1 use\n"
        "A3 ctor\n"
        "A0 dtor\n"
        "A3 dtor\n"
        "A1 dtor\n");
}
